In a principal aspect the present invention relates to a tool for spreading the disc pads of a vehicle disc brake assembly so that the pads may be replaced. The invention thus comprises a manually actuated disc pad spreading tool.
In the repair of vehicles and, for example, with respect to the repair of vehicle braking systems, many special tools are desirable. Disc brakes typically include a caliper housing which is mounted adjacent a wheel. The housing includes opposed disc pads for clamping a disc associated with a wheel of the vehicle. From time to time, it is necessary to replace the pads due to the fact that they wear from frictional contact with the rotating disc. In such circumstances, the caliper housing is typically removed from the wheel assembly of the vehicle, and the disc pads are caused to be spread. The spread pads may then be easily removed and replaced. The caliper housing may then be replaced in the wheel assembly positioned for engagement with the brake disc.
Heretofore, applicants' assignee has made available in the marketplace a disc brake pad spreader tool, Lisle Product Model No. 24400. The Model No. 24400 disc brake pad spreader comprises a plate having a threaded rod through the center of the plate with a plunger mounted on the end of the rod. The plunger and plate are positioned between the opposed pads of a disc brake caliper and are separable by rotating the threaded bolt or rod which connects the plate and plunger.
The described mechanism works quite well and has been widely accepted by automechanics responsible for the repair of disc brakes. A difficulty associated with such a construction, however, is the manual effort often required to effect spreading the disc brake pads. That is, turning the threaded rod may be difficult because the brake piston which drives the pads together may be difficult to reposition or move, and because it impinges against one of the pads, pad separation will be difficult. Thus, there has developed a need for an improved disc brake pad spreading tool which can effectively spread the pads mounted in the caliper housing and which can also compress the piston associated with the caliper housing.